package com.qcloud.utils;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;

import java.util.Arrays;

/**
 * Created by YYY on 2017/7/9.
 */
public class Base64Url {

    static byte base64_table_url[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',

            'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',

            'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',

            'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u',

            'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',

            '8', '9', '*', '-', '\0' };



    static byte base64_pad_url = '_';



    static short base64_reverse_table_url[] = { -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            62, -1, -1, 63, -1, -1, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1,

            -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,

            13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1,

            -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,

            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

            -1, -1, -1, -1, -1, -1, -1, -1 };



    public static int unsignedToBytes(int b) {

        return b & 0xFF;

    }



    // int base64_encode_url(const unsigned char *in_str, int length, char

    // *out_str,int *ret_length)

    public static byte[] base64EncodeUrl(byte[] in_str) {

        byte[] out_str = new byte[1024];



        int out_current = 0;

        int current = 0;

        int length = in_str.length;



        while (length > 2) { /* keep going until we have less than 24 bits */



            out_str[out_current++] = base64_table_url[unsignedToBytes((unsignedToBytes(in_str[current]) >>> 2))];

            out_str[out_current++] = base64_table_url[unsignedToBytes(unsignedToBytes(unsignedToBytes(in_str[current]) & 0x03) << 4)

                    + unsignedToBytes((unsignedToBytes(in_str[current + 1]) >>> 4))];

            out_str[out_current++] = base64_table_url[(unsignedToBytes((unsignedToBytes(in_str[current + 1]) & 0x0f)) << 2)

                    + unsignedToBytes((unsignedToBytes(in_str[current + 2]) >>> 6))];

            out_str[out_current++] = base64_table_url[unsignedToBytes((unsignedToBytes(in_str[current + 2]) & 0x3f))];

            current += 3;

            length -= 3; /* we just handle 3 octets of data */

        }



		/* now deal with the tail end of things */

        if (length != 0) {

            out_str[out_current++] = base64_table_url[unsignedToBytes(in_str[current]) >>> 2];

            if (length > 1) {

                out_str[out_current++] = base64_table_url[unsignedToBytes((unsignedToBytes(in_str[current]) & 0x03) << 4)

                        + unsignedToBytes(unsignedToBytes(in_str[current + 1]) >>> 4)];

                out_str[out_current++] = base64_table_url[unsignedToBytes((unsignedToBytes(in_str[current + 1]) & 0x0f) << 2)];

                out_str[out_current++] = base64_pad_url;

            } else {

                out_str[out_current++] = base64_table_url[unsignedToBytes((unsignedToBytes(in_str[current]) & 0x03) << 4)];

                out_str[out_current++] = base64_pad_url;

                out_str[out_current++] = base64_pad_url;

            }

        }



        // System.out.println("length in base64EncodeUrl: " + out_current );

        byte[] out_bytes = new String(out_str).getBytes();

        return Arrays.copyOfRange(out_bytes, 0, out_current);

    }



    // int base64_decode_url(const unsigned char *in_str, int length, char

    // *out_str, int *ret_length)

    public static byte[] base64DecodeUrl(byte[] in_str) {

        // const unsigned char *current = in_str;

        int ch, i = 0, j = 0, k;

        int current = 0;

        byte[] out_str = new byte[1024];

        int length = in_str.length;

		/* this sucks for threaded environments */



		/* run through the whole string, converting as we go */

        // while ((ch = in_str[current++]) != '\0' && length-- > 0) {

        ch = in_str[0];

        while (length-- > 0) {

            ch = in_str[current++];

            if (ch == base64_pad_url)

                break;

			/*

			 * When Base64 gets POSTed, all pluses are interpreted as spaces.

			 * This line changes them back. It's not exactly the Base64 spec,

			 * but it is completely compatible with it (the spec says that

			 * spaces are invalid). This will also save many people considerable

			 * headache. - Turadg Aleahmad <turadg@wise.berkeley.edu>

			 */

            if (ch == ' ')

                ch = '*'; // never using '+'



            ch = base64_reverse_table_url[ch];

            if (ch < 0)

                continue;



            switch (i % 4) {

                case 0:

                    out_str[j] = (byte) unsignedToBytes(unsignedToBytes(ch) << 2);

                    break;

                case 1:

                    out_str[j++] |= (byte) unsignedToBytes(unsignedToBytes(ch) >>> 4);

                    out_str[j] = (byte) unsignedToBytes(unsignedToBytes(unsignedToBytes(ch) & 0x0f) << 4);

                    break;

                case 2:

                    out_str[j++] |= (byte) unsignedToBytes(unsignedToBytes(ch) >>> 2);

                    out_str[j] = (byte) unsignedToBytes(unsignedToBytes(unsignedToBytes(ch) & 0x03) << 6);

                    break;

                case 3:

                    out_str[j++] |= (byte) unsignedToBytes(ch);

                    break;

            }

            i++;

        }

        k = j;

		/* mop things up if we ended on a boundary */

        if (ch == base64_pad_url) {

            switch (i % 4) {

                case 0:

                case 1:

                    byte[] error = new byte[1];

                    error[0] = '\0';

                    return error;

                case 2:

                    k++;

                case 3:

                    out_str[k++] = 0;

            }

        }

        return Arrays.copyOfRange(out_str, 0, j);

    }



    public static void main(String[] args) throws DecoderException {



        // String hexString = "5095";

        String hexString = "789c6d8d4d4f83401884ff0b578c5dba0bbb98782015b1a1f8059a7222743fc8da96aecbdbdad6f8dfa5046fce6de6c9cc7c3bc522bfeec4baaa8dd1c2b9713c822e0a7ddfb91aa03c1a6d65552b90b6e794d2a0e7231c5a550d15b6ff96416fe590e38051c2281d732d640b5ae96172ea051c29be524c62e463e57382e854a08020a578c8febe38dfed5ba8e0642e9b98e21174bae97d16bfcde633299e0f49c81f27a26490b97665d7675dd0fdc35df1de994d23bc4301db349fbb918ea3e36b509878f7956d84dbb44b4ed23287b454f7119c12fea4968b64927d7c962179b9757e7e01ed1059d9";



        byte[] test = Hex.decodeHex(hexString.toCharArray());

        byte[] compressBytes = base64EncodeUrl(test);

        System.out.println("compress : " + new String(compressBytes));

        byte[] uncompressBytes = base64DecodeUrl(compressBytes);

        System.out.println("uncompress: "

                + Hex.encodeHexString(uncompressBytes));

    }

}